The subject matter disclosed herein relates to turbomachines and, more particularly, to turbine engines having aerodynamic elements configured to provide for delayed flow separation.
A typical turbomachine, such as a gas turbine engine, includes a compressor, a combustor, a turbine and a diffuser. The compressor compresses inlet air and the combustor combusts the compressed inlet air along with fuel. The high energy products of this combustion are directed toward the turbine where they are expanded in power generation operations. The diffuser is disposed downstream from the turbine and serves to reduce the remaining energy of the combustion products before they are exhausted to the atmosphere.
Generally, the diffuser includes an outer wall, a center body disposed within the outer wall to define an annular pathway and one or more vanes traversing the annular pathway. During baseline turbomachine operations, velocities of the combustion products flowing through the diffuser are sufficiently high and flow separation from the surfaces of the one or more vanes is not exhibited. However, at part load operations, such as gas turbine engine start-up or turn-down sequences, the combustion product velocities are reduced or high angle-of-attack conditions are in effect and flow separation tends to occur. This flow separation leads to decreased performance of the diffuser.